Change speed gear



Oct. 29, 1935. FERRARI 2,019,006

CHANGE SPEED GEAR Filed Feb. 1, 1934 3 Sheets-Sheet 1 3s ZZZ l 2O \29 12Z 24 50 i Oct. 2 9

CHANGE SPEED G Filed Feb- 1934 3 Sheet 2 Oct. 29, 1935. FERRAR|2,019,006

CHANGE SPEED GEAR Filed Feb. 1, 1934 3 Sheets-Sheet 3 %I ///%I///%I% Q 532 eA/7'oI Patented Oct. 29, 1935 UNITED STATES PATENT OFFICE- CHANGESPEED GEAR Lorenzo Ferrari, Genoa, Italy Application February 1, 1934,Serial No. 709,375

5 Claims. (c1. 14-201) This invention relates to change speed gears andits object is to provide a device of this kind that may be fitted to anyrotating device and especially on motor cars or the like and allows 5gradual change of the speed of the receiving shaft without firstdisengaging the clutch.

According to the invention this end is attained by providing an inclineddrum having two an- 120 Figure 1 of the lower part of the change speedgear.

F ure 3' is a transversal section on line III-I11 of Figure 1.

Figure 4 shows a modification of the worm 95 drive shown in Figures 1and 3.

Figure 5 is a detail section of a variation of the connection betweenthe annular member and the drum, by the insertion of ball bearings.

Figure 6 shows a modification of arrangement 30 shown in Figure 2; and

Figures 7 and'8 show in plan view part of one of the plates indented atits border for use with the embodiment shown in Figure 6.

According to the invention, to the driving 35 shaft II a transmissionplate I2 is fastened that rotates in a bearing |3 of a casing |4enclosing the whole change speed gear. The casing H has further anintermediate fiange providing a bearing l5 for a rotatable membercomprising a plate l6 opposite to plate l2 and a bell-like memher I!having a toothed crown 8. This member l6, I1 is rotatably mounted onshaft H and within bearing l5. Between plates l2 and IS an inclined drum|9 is fitted provided, at its ends 46 with annular adherence members,that in the case as shown are constituted by rubber rings 20, 20'. DrumI9 is mounted within a collar 2| having pivots 22 rotatable in bearingsof a frame 23, and is kept with its adherence rings 20, 20'

.50 into driving contact with plates I2 and I6, by a spring 24 attachedby one of its ends to a pin 25 fastened to casing I4 and by the otherend to a lever arm 26 integral with collar 2| rotatably mounted in anannular groove formed in the 68 cylindrical part of drum l9;

Frame 23 is slidably mounted on guides 21 and may be shifted along theseguides by means of toothed sectors 28 engaging rack teeth 29 formed atthe lower border of frame 23. Sector 28 is keyed to a shaft 50 rotatablein bearings of casing 4 and passing through this latter member.

Suitable means are fitted to the exterior of this casing for oscillatingthis sector. In this manner frame 23 with collar 2| and drum I9 may beshifted horizontally, so that the adherence members 20, are allowed toslide radially along plates l2 and l6.

Within an axial cavity of shaft H a projection 3|] of a second shaft 3|is rotatably mounted 15 integral with a helical gear 32 in mesh with apair of worm gears 33, 33'. Worms33, 33', are each fitted to one end ofshafts 34, 34' to the other end of which'pinions 48 and 48' are fitted,in mesh with gear l8 of bell l1. Shafts 34, 34 30 are rotatable inbearings of a block 35 rotatably supported within a bearing 36 of casingl4. Within this bearing 36 a shouldered hub3l is also rotatably mounted,integral with a gear 38'.

comprising an outer conical gear and an inner cylindrical tooth crownconstituting a clutch member. A second like gear 39 provided with ablind shouldered hub 40, constituting the first portion of the drivenshaft, is rotatably mounted on the stub end of shaft 3| and within abearing formed in an end hub 4| of easing. On shaft 3| a double clutch42, 42 is slidable, and a shift lever 43 is provided for shifting thisdouble gear 42, 42' to mesh with either of the gears 38,39, or to leavesame in an intermediate idle posi-' tion, as shown. Lever 43 may besingularly oscillated by known means from the exterior of cas-. ing l4.However gears 38 and 39 are coupled together through their bevel partsby an intermediate bevel gear 44 mounted on stub shaft 45 fitted tocasing l4.

The operation of the device is as follows: Assuming drum l9 to beconcentrical with shaft H, by rotating this latter, plate |2 will drivedrum l9 and this in its turn will drive plate H6 at the same speed asplate l2. Toothed bell l8 will thus rotate at the same speed as shaftand thus the whole device will rotate as it were in a single piece. Thisposition of drum |9 corresponds to direct coupling. 3

Now by operating lever 28, so as to shift fram 23 towards the right ofFigure 1, owing to the difference of the contact'radii of plates l2 andIS with the adherence rings 20, 20' of drum 9, plate IE will be drivenat a speed thatis less than that of plate l2. This difference will bemultiplied by the worm drive 33, 32, 33' and, owing to the turningdirection of the thread of worms 33, 33', the shaft 3i will be driven ina turning direction that is opposite to that of shaft ll. be thusproportional to a multiple of the difference of speed of plates I2 and I6. Thus at a certain time, when shafts I I and 3| turn at the same speedin opposite directions, the driven shaft 40 will stop.

Beyond this limit, a reverse movement of the driven shaft will result.

In practice however the reversion of the turnins di ection .of thedriven shaft is eifected through double clutch gear 42, 42' which isshifted by leverji.

When gear 42, I2 is shifted in the idle position as shown in Figure 1,shaft ll will be stopped. When gear 39 is'clutched, the driven shaftintegral with hub 40 will be driven in the same direction as the drivingshaft; when gear 38 is clutched, a reverse movement of the driven shaftwill result. v

The reversion of the turning direction of driven shaft'will be eii'ectedprogressively, by gradually reducing to nil the speed of the drivenshaft.

The pitch of the worm 33, 33 will be chosen so as to reduce to a minimumthe resistance of plate It to its driving by means of drum I9 and thusin some cases rubber rings 20 and 20' will be suiiicient to resist thestresses set up by their frictional engagement with plates l2 and It. Insome cases however the engagement between the borders of drum I! and theplates l2 and I 6 might be effected by other known means, as indentedsurfaces, and so on.

It is apparent that many variations of the device as just described arepossible, though remaining within the limits of the invention.

Thus the adherence between drum l9 and plates l2 and I 6 could beeffected by means of a crown of spring-pressed members 46, Figure 6,engaging radial or parallel indentations of plates I! and 16, whichcould be made as shown in Figure 7 or 8. Furthermore the collar 2| couldbe The turning speed of driven shaft 40, will mounted on thecorresponding annular groove of drum 1! on suitable ball bearings 41, asshown in Figure 5.

The worm gears I3, 33 could also be actuated through intermediatepinions ll, 48' by diametrically oppomte pinions ll, 49 engaging theteeth 18 of bell l1.

Having thus described my invention, I claim:

1. In a change speed gear, the combination of a driving shaft, a plateon said shaft, a driven m shaft, a second plate facing the first namedplate having connection with the driven shaft, a casing enclosing andsupporting said plates and said shafts, a transverse. guide memberwithin said casing intermediate said plates, a frame is slidably mountedon said guide member, means for positively shifting said frame alongsaid guide member, bearings at opposite points of said frame, a collarhaving diametrically opposed pivots journaled in said bearings, a drumrotatably mounted in said collar, driving members on the borders of saiddrum establishing a driving connection between said drum and theopposite plates, means for maintaining said drum in an inclined positionwith the diametrically opposed points of the driv- 1| ing members incontact with said two plates.

2. A change speed gear as claimed in claim 1 characterized in that saiddriving members are constituted by rubber rings.

3. A change speed gear as claimed in claim 1 I characterized in thatsaid means for maintaining the drum' in an inclined position isconstituted by a spring secured at one end to the easing and at theother end to said drum.

4.Achangespeedgearasclaimedinclaiml characterized in that said means forshifting said frame is constituted by teeth formed on the frame and atoothed sector engaging said teeth and a shaft supporting said sector.

5. A change speed gear as claimed in claim l characterized in that saiddriving members are constituted by spring teeth fitted in said drum, andteeth on said plates engaged by the first mentioned teeth.

LORENZO FERRARI.

